The conventional continuous oven typically consists of a so-called tunnel oven in which works typically consisting of planar electronic component parts are carried by a belt conveyor from an inlet end of the oven, and are discharged from an outlet end of the oven after being heated inside the oven while being thus conveyed. According to this conventional continuous oven, a plurality of works are conveyed in a single row, and are required to be kept inside the oven for a sufficient period of time. Therefore, in order to achieve a sufficient throughput, the overall length of the oven is required to be substantial, and a corresponding large floor space is required for the installation of the continuous oven.